巯基乙胺自组装膜表面润湿性的变化  

Real time Characterization for Surface Wettibility of Cysteamine Self asembled Monolayers on Gold

作　　者：赵健伟[1] 于化忠[1] 王永强[1] 刘忠范[1] 

机构地区：[1]北京大学化学与分子工程学院智能材料研究中心

出　　处：《高等学校化学学报》1998年第3期464-468,共5页Chemical Journal of Chinese Universities

基　　金：国家攀登计划基金

摘　　要：报道了巯基乙胺自组装膜在不同的时间尺度内表面润湿性的特征变化．利用接触角滴定方法对其表面状态进行实时监控表明，自组装膜由固／液界面转移至固／气界面后，接触角在短时间内经历了一个快速升高过程和一个相对较慢的变化过程．从表面自由能的角度，讨论了该现象的机理．采用不同ｐＨ值的缓冲溶液进行接触角滴定，得到了巯基乙胺自组装膜的滴定曲线，从而确定表面ｐＫｂ值为１．７±０．２．从接触角滴定曲线在长时间内的变化趋势中发现，ｐＫｂ值无显著变化，但曲线整体向上平移，并且滴定曲线中上下平台的差值随时间增长而减小．The characteristic change of surface wettibility of cysteamine self assembled monolayers was reported. Contact angle titration method was used to carry out the real time measurements of the surface wettibility of the monolayers which were formed by dipping gold substrate into dilute HSCH 2CH 2NH 2/CH 3CH 2OH solution. After the monolayers transfered from solid/liquid interface to solid/air interface, the contact angles of the monolayers underwent a sharp increase, then got down to a slow variation process. From the perspective surface free energy, the structural rearrangement of monolayers was considered as the main reason for such a phenomenon. The contact angle titration curve for basic group tailored SAMs was obtained by using a series of solutions with different pH values. The p K b value of cysteamine SAMs was derived to be 1.7±0.2. Based on above characterization, the change of surface wettibility for the monolayers was further studied at a long time scale by taking account of changes in p K b and △ θ (difference between two plateaus of the contact angle titration curve).

关 键 词：巯基乙胺 自组装膜 接触角滴定 表面湿润性 SAMS 

分 类 号：O647.1[理学—物理化学]